Automatic telephone-exchange system.



C. A. W. HULTMAN.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAR. 15, T915.

Patented Dec. 18, 1917.

4 SHEETSSHEET I.

i fucaoca 7 {amp/fin C. A W. HULTMAN.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAR. 15, 1915.

1,250,885. Patented Dec. 18,1917.

4 SHEETS-SHEET 2.

C. A. W. HULTMAN.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION HLED MAR. 15. 1915.

1,250,885. Patented De0.18,1917.

4 SHEETSSHEET 3.

fmcosco w C. A. W. HULTMAN.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAR. 15, \915.

1,250,885. Patented Dec.18,1917.

4 SHEETSSHEET 4- w mvam fo c 1 V1 h moses m 5 w FICE.

CARL AXEL WILHEIJM HULTMAN, 0F STOCKHOLM, SWEDEN.

AUTOMATIC TELEHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Dec. 18, 1917.

Application filed March 15, 1915. I Serial No. 14,380.

T 0 all whom it may concern.

Be it known that I, CARL AXEL \VILHELM HL'LTMAX, director, a subject of the King of Sweden, residing at J akobsbergsgatan 24, Stockholm, Sweden, have invented certain new and useful Improvements in Automatic Telephone- Exchange Systems, of which the following a specification.

It has been proposed in order to diminish the number of movable parts in automatic telephone exchange systems to use so-called connectors for up to 10,000 subscribers instead ofas is the case in some systemsconnectors for only 100 to 200 subscribers. Py using such greater connectors the number of so-called selectors is reduced to a single one for up to 100,000 subscribers.

In such greater connectors, however, the inconvenience will arise, that in case the wires of the subscribers are for instance arranged in groups, each containing 100 wires in width and 100 wires in height, the switching organ, movable in the connector and completing the coupling, must under certain circumstances be moved up to 100 steps in the one and the same number of steps in the other direction, which will considerably delay the coupling.

This inconvenience will be avoided according to the present invention which consists in arranging the subscribers wires or their end contacts in groups and in arranging the switching organ in such a way in relation to said groups as to make it possible to move the said organ to the one or the other of said groups. Suitably four groups are used, two on the right and two on the left hand of the switching organ, two of said groups being arranged under and two above the switching organ.

For 10,000 subscribers four groups will in this way be obtained, each one containing the wires of 2500 subscribers, arranged in groups of 50 in width and 50 in height. In this way the switching organ need not move more than up to 50 steps in the one and up to 50 steps in the other direction. On the other hand the motion will take place alternating to the right upwardly, to the right downwardly, to the left upwardly or to the left downwardly.

For obtaining the said different motions a number of devices will of course be necessary, which will in the following be more fully described.

The division in groups can of course be made in many difl erentways, as the relative position of the groups as well as their number can considerably be varied.

In the following the invention is described as used in connection with an automatic telephone exchange system of the kind, where the subscribers wires or ribs, connected theretouncovered or provided with contacts-are parallel and are arranged with interspaces, wherein the switching organs are movable. In such a system the invention is especially useful not only on account of the increased rapidity in the switching operation but also on account thereof that the switching organs, which move between the wires, must be made as short as possible in order that a good and effective guidance thereof may be obtained. It is then of importance that the number of subscribers wires, arranged above each other, is not too great.

In the annexed drawings Figure 1 shows schematically a telephone exchange system according to the present invention.

Figs. 2 and 2 and 2 show a coupling diagran i and Fig. 3 a diagrammatic view of a preferred embodiment of a device for moving the switching organ.

A is the switching organ and its corresponding mechanism and B B B and B four groups of subscribers wires E surrounding A. In connecting two subscribers the switching organ A will at first move to the right or to the left in the direction of the arrow C or C and thereafter it will move upwardly or downwardly in the direction of the arrow D or D depending upon in which group the called subscribers wires, ribs or contacts are situated.

The order of motion can of course be reversed, so that the vertical motion will take place at first and the horizontal motion thereafter.

From Fig. 1 the principal difference between the present system and known systems will be clear. The switching organ and its mechanism has hitherto always been arranged as is indicated in dotted lines at A For 10,000 subscribers, arranged 100x100, it has been necessary in order that A should reach the subscriber highest to the right to move A 100 steps to the right i and thereinafter to move it 100 steps up wardly; according to the present invention 50 steps to the right and 50 steps upwardly are suiiicient. By this construction the advantage is obtained that the switching operation consumes comparatively short time and that the motion of the switch is short and therefore more steady and secure.

In Figs. 2, 2 and 2 a coupling diagram is shown, showing in detail the connections in a system according to the invention. Before this diagram is described, it will be necessary to describe some of the most important switching elements.

A. The most important switching elements in the present telephone erehange system.

As in the most of the known telephone exchange systems a calling subscriber will at first operate a first preselector. The number thereof is quite the same as that of the subscribers; a first preselector is thus arranged for every subscriber. From this first preselector the subscriber will then operate a vacant second preselector. The number thereof is for instance 1,000 if 10,000 subscribers are connected.

For the above named number of subscribers the number of selectors is suitably 500 to 600. In connection with each selector a reversing device and a register device is arranged. These devices will now be operated by the subscriber by means of the usual finger disk arranged at the apparatus. The register device is operated by means of the finger disk and after it has been brought to the positions corresponding to the figure of the subscriber, the motion of the switching organ can take place.

If the number of subscribers is greater than 10,000, it is necessary to arrange for each of the 10,000 subscribers a so-called selector with connector-finder. It. is not suitable to arrange in each group, for instance B in Fig. 1, more than 2,500 subscribers wires. In Figs. 2 and 2* three connector-finders are shown, corresponding to a central with up to 30,000 subscribers.

In correspondence to the position of the register device the switching organ must move to the right or to the left, upwardly or downwardly, depending upon in which of the B-groups in Fig. 1 the called subscribers wires, ribs or contacts are located. This is performed by means of special relays,

- whereof the one or the other is operated depending upon the position of the register device. The said relays transmit the conmenses nection of the switching organ to machineoperated organs, movable to the right or to the left and upwardly or downwardly. It is also possible to arrange the connections in such a way that the relays transmit the motion of said organs in one or the other direction. 1

In Figs. 2, 2- and 2 a and Z) are the two service lines. at is an auxiliary line. It is possible to make up a system wherein the switching organ is operated by the aid of the aZ-line, but wherein all impulses are sent through the eand b-lines.

It is, however, also possible to operate the switching organ alternating by the aid of the Z2- and d-lines, and to let all impulses pass through the (Z-line and one of the speech lines. Such a system is shown in Figs. 2,

B. A switching system wherein the switching organ is operated by the 07 an auxiliary line and one of the speech Zines.

Because the two preselectors over which the subscriber will reach the selector, are ar-. ranged in a known manner, perform a known purpose and are of no importance at all for setting forth the present invention, they are not shown or described. From the second preselector are drawn the speech lines a and b as well as an auxiliary line (l.

l. The selector.

\Vhen the second preselector has stopped, the subscriber has been connect-ed to the selector and he can thus begin to operate his finger disk. The a-line of the subscriber is now connected with the line-relay LR over the contact 21. the point w and the rest contact in the 9th position of the first part I of the reversing devices 0. The b-line of the subscriber is connected with the line-relay LR over the contact 22, the point 1 the contact 151 and the rest con tact in the 9th position of the second part II of the reversing device 0.

LR and LR, are both connected with the battery BB.

The different contacts in O are hereafter marked I: 9 or IV: 6 and so on; this means the contact 9 in the part I or the contact 6 in the part IV and so on. The four arms of I-IV are arranged on a common shaft bearing also a tooth wheel, operated by the electromagnet OE.

When the subscriber now sends current impulses on the a line, they will excite LR and the contact 23 is alternatingly opened and closed. Every time 23 is closed. the following circuit closed: each, 23 Izl (the reversing device in its first position) and the first register RE, to the battery. The register RE, (10,000-figure register) is in this way moved av certain number of steps menses corresponding to the first digit in the desired figure. When after the impulses on the a-linc an impulse is sent on the b-line (the said impulse is automatically sent out by the finger disk), the relay LR is excited and the contact 21 is closed for a moment. Hereby the following circuit is closed: earth, 24:, 11:1, the upper coil OE of the electromagnet of the reversing device and the battery. The electromagnet OE is excited and when it is again released, the reversing device is moved to the second position. The subscriber will now again send impulses upon the a-line, which will again operate the relay LE On account of the position of the reversing device 0 the said impulses are sent to the register RE (IOOO-figure register) which will take the position corresponding to the second digit whereupon the electromagnet of the reversing device quite as before will obtain an impulse and the reversing device will move to the'third position.

In the same way the registers RE (100- figure register), 'RE, (-figure register) and RE, (unit-register) are operated and the reversing device will move step by step to its 6th position.

In this position the following circuit is closed: earth, 111:6, the relay U R and the battery BB.

Hereby the contacts 21 and 22 are released, 2'. e, the subscribers line is shut off from communication with the selector and this state will prevail also at 111:7 and 111:8. Besides a connection with earth is obtained over 111:6 and the contact 25 of the register RE, to the magnetic clutch MK, of the selector. The said clutch is inserted between the arm of the selector and its shaft, driven mechanically. The contact 25 was closed at the moment the register RE, left its rest-position. Vhen the electromagnet clutch MK is excited. the selector is in motion mechanically and begins to rotate.

During this rotation the register RE, is moved step by step by its obtaining intermittent current impulses from the battery through the register RE over 1:1 (the bottom contact) the outermost ring of the selector, the corresponding contact spring and the earth connection. In this way the register RE, will follow the rotation of the selector until it has reached the rest position when the contact 25 is opened. Then the clutch electromagnet MK will be released and the selector will stop. In this way the selector has been brought to a position, dependent upon the position the register RE, has obtained on account of the first series of impulses from the subscriber. The toothed wheel of the register RE, as well as the toothed wheel of the other registers is provided with 11 teeth; the selector on the contrary is provided with 10 earthconnections. If the subscriber had only sent a single impulse in the first series, the register RE has thus 10 steps to move before the normal position has been reached. The selector will thus rotate until it has passed 10 earth-connections and it will thus at this moment, when it stops, be connected to the first 10,000-figure group of subscribers. In case the subscriber should have in the first series sent out 2 impulses, 9 earth-connections from the selector are necessary for bringing the register RE, back to the rest position, and

the selector will then rotate until the next contact group from the last one is reached. corresponding to the second 10,000-figure and so on.

When the register RE, has reached again its rest or initial position, the contact 26 is closed, whereby the following circuit is closed; earth, 111: 6, 26, the contact 152 and through the start relay R, to the battery. As soon as the relay R is excited, its contact 153 will be closed, whereby the following circuit will be closed: earth, 153, the clutch electromagnct MK, to the battery.

The said electromagnet, which when excited will connect the arm of the connectorfinder with the i'nechanically operated shaft at", will thus obtain current in the above way and the connector-tinder will begin to ro tate and will continue its rotation until a vacant connector is found, that is until in the engaged part of the connector-finder an earth-connected c-contact is found. At this moment current will be obtained through the test relay Ly R along the following way: the battery, the contact 154 of R Lil/R the long d-rib of the selector, the corresponding c-contact to the engaged test-plate in the selector and further over the connection with the corresponding section of the connector-finder and over a contact in this section to earth through a resistance coil R The relay Lg R is thus excited and its contact 152 is released, whereby the relay R, will be released. Hereby the contact 153 is released and the electromagnet MK, will also be released, this causing the connectorfinder to stop. While the relay 11 11,, was excited. its contact 155 was closed so that the greater part of lily R, was short-circuitcd and battery is now out in over 155 and the contact 156 in the selector (closed as soon as the selector leaves its initial position) in stead of over the contact 15a of the relay R, (this contact was for the rest opened the moment after Ly R, had been excited). By the shortcircuiting of the greater part of the relay Lg R, nearly the full battery tension will be obtained on that c-line, which corresponds to the connector as selected; the said connector willv thus be marked engaged. A test relay (Lg R belonging to a connectortinder, rotating for finding or selecting a vacant connector cannot be excited by the very low difference in tension, which this relay will obtain, when the one end contact thereof is directly connected with the battery (over the contact 154) while the other end contact is connected with the c-contact, whose tension is only a very little lower on account of the shortcircuiting of the greater part of a test-relay, as stated above. When the relay R, was excited, its contact 157 was closed whereby the current could pass through the electromagnet OE and when the relay R, is released when the connectorfind er has stopped, the reversing device will move into its 7th position.

ll. The connector.

As soon as the selector has in the way described above selected a connector belonging to that 10.000-figure of subscribers wires, corresponding to the first digit in the figure desired by the calling subscriber, the switching organ of this connector is to be moved for selecting the line in question.

a. The horizontal motion of the switching organ.

In conformity with the number of impulses which the subscriber had sent out for the second digit in the desired subscribers figure, the register RE had been brought to rotate a greater or less number of steps. The cam y will hold the contact 82, controlling the motion of the switching organ to the right or to the left, closed during the first to the fifth step of RE lVe assume, in the first case, that the second series of impulses from the subscribers apparatus has been for instance 9; the contact 32 will thus be released. \Vhen the reversing device after the register RE, having been restored moved to the 7th position, the following circuit was closed: earth J. 33 on the register RE, (was closed when RE, left its initial position), IV: 7, the electromagnet 0 E and the battery. The said electromagnet will consequently be excited. On the closing of its contact 158 the following circuit will be closed: earth, 33, IV:7, 158, 159 of the electromagnet V, the long d-rib of the selector and over the engaged d-contact of the long (Z-rib in the selected section of the connector-finder and further over the (Z- line to the selected connector and finally over the starting relay S, R, over the contact 160 and the contact 161 (of the back relay BR,) to the battery. S, R, will suitably be excited and its contact 162 will be closed, whereby the following circuit-will be obtained: the battery, 16?, the clutch electromagnet M, K,. the bottom winding of the auxiliary relay HR, and earth. When M, K, is hereby excited, the switching organ teac es will be moved to the right between B, and B, in Fig. l for selecting the 100-figure within which the called subscribers line is located.

It is to be observed, that the relays S, R, and S, R, are at work only when the switching organ is to be moved to the right or to the left and that they will control the horizontal motion of the said organ. The relays S, R, and S, It, on the contrary will control the vertical motion of the switching organ.

The clutch, electrom-agnets and their mannor of controlling the motion of the switching organ will be described at the end of the specification in connection with the description of Fig. 3.

At the beginning of the just named motion of the switching organ the contact 160 is released, but this is without any infiuence upon the current through the relay S, R,, since S, R, on being excited had been connected with battery over its own contact 163 and the contact 164. M, K, being excited, its contact 165 is closed, whereby the b-line is connected to the long b-ribs for the horizontal and the vertical motion. The corresponding long aribs are in permanent connection with the aline to the selector. For the sake of space the ribs 0: and Z) of the connector are in this scheme placed horizontally, though of course one series must be placed horizontally and the other vertically.

During the continued motion of the switching organ the slip springs S, will intermittently connect the aand h-lines with earth, while one of two mutually connected springs slips respectively upon the long aand b-ledges and the other upon ledges, provided with grounded plates. In the present case at first a grounding on the a-line will be obtained, which will pass over the connector-finder the selector, 00,, the rest contact in 1:9 through the relay LR, to the battery. When the relay LR is excited 23 is closed whereby a circuit is obtained from earth over 23, 1:7, 112, RE, and to the battery, whereby the register RE, is put in motion and will thus turn a step. When RE, on account of the curernt impulses from the subscriber has turned 9 steps and on account of the. just named grounding on the a-line has turned another step, it will. remain a further step, until the register RE, has reached its initial position.

After the grounding on the (eline 10 groundings on the b-line will be obtained and these are transmitted over the connectorfinder and the selector over the point 9 166 on V and over 1V1!) through the relay LR, to the battery. (The circuit over 151 on UR is broken, as UR is continually excited). The relay LR, will thus obtain 10 current impulses and its contact 24 be closed as many times. The groundings, hereby obtained,

ea set which should be transmitted over 24, H27, the contact 14 of RE and through RE, to the battery, are however not obtained, as long as it is released, it is as longas the register RE, has not as yet returned to its initial position. After the ten groundings on the b-line another grounding is obtained upon the a-line and this grounding is in the same way as before transmitted to the relay LR whereby RE, is brought to turn further a step so that it has reached its initial position and 41 will thus be closed.

The following impulses on the b-line can consequently now operate the'register RE, and bring it to its initial position. At the moment this occurs, its contact 33 will be released, whereby that grounding will cease, which has over it controlled partly the relay E and partly over 158 on 0 E and over the selector and the connector-finder the relay S, R, of the con nector. When S, R, is released, the contact 162 is released, which will also release the electromagnet M, K, and the'horizontal motion of the switching organ will cease. As the relay HR, is put in series with M, K,, HR, will be released at the same moment as M, K,. \Vhen HR, was excited at the beginning of the motion, its contact 167 was closed, whereby current was obtained from the battery over 167 through the clutch electromagnet MB, to earth. Hereby the switching organ was free to move horizontally but will be locked when MB, is released at the moment 167 is released at the relay HR, reaching its position of rest.

By the closing of the contact 167 a circuit will be closed over battery, 167, the relay R, the contact 168, to earth. This contact was closed at the moment the horizontal motion began. R will thus be excited and will upon the closing of its contact 169 obtain an exciting current, while the battery will be switched to the relay over 169 and 64 of the releasing magnet AR of the connector, which will cause R to be excited even after the releasing of 167 on HR,. That the relay R has been excited is, however, of no importance during this phase of the switching operation, but is of importance when hereafter the disconnecting of the subscribers takes place. Upon the cnergization of HR,, its contacts 17 017 l and 172 were released, preventing respectively S R,, S R, and the back relay BR from being operated. As before stated, the relay 0 E, of the selector was operated at the moment when the reversing device O reached its 7th position and hereby the contact 173 was closed, whereby the following circuit was closed: earth, 17 3 and the top winding of the electromagnet OE to the battery. OE will thus be excited and when afterward the contact 173 is released at the moment when the register RE,

reaches its initial position, that is at the moment the horizontal motion of the switching organ ceases, the reversing device 0 will turn to its eighth position.

The just described operations take place if the second digit in the called subscribers figure had been 60. Should, however, the said digit have been for instance 2 the register under the action of the second series of current impulses from the subscriber turned two steps and consequently the cam 9, would have held the contact 32 closed. In consequence hereof at the moment the reversing device after a vacant connector had been found had reached its 7 th position, the following circuit would have been closed: earth 32, IV:7 (the inner contact) and over the relay V to the battery. This relay will thus be excited simultaneously with the relay 0, E, as has hereinbefore been described by the closing of the contact 33 on TRE When V is excited, its contact 174 is closed and hereby the following circuit is closed; earth, 33,1Vz7 (the outer contact), 158 (of 0 E 174, the point 3/ and over the selector and the connectorfinder the b-line to the connector and over its relay S, R, and over the contacts 175 and 161 to the battery. In consequence hereof in this case the relay S, R, will thus be operated instead of S, R, and this will cause the switching organ to move to the left instead of to the right as before described. When namely S, R, is excited its contact 176 will be closed, whereby the following circuit is closed: the battery, 176, M, K, and the upper winding of HR, to earth. M, K which will control the mo tion to the left, will thus be excited and the switching organ will begin to move to the left.

The contact 177 being closed the long I)- ribs in the connector will be connected to the d-line and the said ribs will on account hereof be connected to the relay LR, over the connector-finder and the selector, the contact 178 of V (closed when V was excited) and IV:9. The a-ribs of the connector will as before be in connection with the relay LE When the switching organ begins its motion to the left, at first 6 impulses are sent out on the a-line and as before the register RE, will turn 6 steps. After these 6 steps the register RE, will be in its 8th position. The contact 32 was released already in the 6th position, but in spite hereof V will continue to be energized, while it is continually energized by a current over its contact 179 as long as 0 E is energized. After the 6 impulses on the a-line impulses will be transmitted on the d-line and the relay LR, will consequently be energized 10 times without operating the register BE, while it of the register RE will continue to be released: After the said 10 impulses a further impulse is transmitted through the a-line and thereinafter further a series of 10 impulses on the (l-line, which will continue to have no effect upon the register RE In this way it will continue until RE after the 9th impulse has reached its initial position, whereafter the impulses upon the (Z-line will operate RE At the moment RE reaches its initial position and its contact 33 is released E and in, R will be released and the motion of the switching organ will cease.

All the t'unctions as has been described above for the other case, of the relays, which also in this latter case are operated, are in this case of the same importance and the contact 180 of S, R, has the same task to operate this relay as 163 has in relation to the relay S, R

6. The cert-2 ml motion of the switching organ.

The horizontal motion having now been completed and the reversing device of the selector having reached its 8th position, the vertical motion is now to begin. At the moment 0 has reached the 8th position, the following circuit will be closed: earth, the contact 51 of RE IV: 8 (the outer contact) and E to the battery. 0 E will thus be excited even now in the same manner as during the horizontal motion and V will also eventually be energized, dependent upon the position of RE, that is if the contact 50 is closed or not. \Ve may assume, that this is not the case and that V thus will not be energized. By the closing oi the contact 158 of 0., E the current is as before transmitted from earth over 51, IVzS, 158, 159. the selector: and the connector-finder over the (l-line to the connector and there over the contact 170 of the relay HR, through the relay S R, to the battery over the contacts 181 and 161. The relay S, R, will thus be energized and will be continually energized by a current over its own contact 182. which will cause that this relay is energized also after the contact 181 has been released at the beginning of the vertical motion. The contact 183 of the relay S R, being closed, current will flow through the clutch electromagnet K, and the upper winding of the relay HR the said two electromagnets being thus energized. The switching organ of the connector will consequently begin to move upwardly and quite in the same way as on the horizontal motion groundings will be obtained on the aand b-lines said groundings moving the registers RE, and RE, to the initial position. The Contact 184 of M 1 has the same function as 165 of M, K,

namely to connect the long b-ribs of the connector with the b-line.

When the relay HR was excited, its contact 185 was closed, whereby the clutch VtB was released, so that the vertical motion can freely take place and when 185 is afterward released, the clutch is again operated for securing the switching organ. The closing of the contact 186 will energize the test relay Ii R so that it will be energized during the whole vertical motion. The releasing of the contact 187 is arranged in order that the c-contact oi the switching organ, which will during the vertical motion slip on the wires in the group, shall not disturb eventual speeches between other subscribers and the releasing of 188 will cut away the ringing relay RR from function.

The relay Lg ll, is energized during the entire vertical motion and the contact 250 is closed and therefore the c-contact which slips on the wires in the group, could disturb eventual speeches, but when the relay HR is energized, its contact 187 is released and the c-contact (shown at the right of Fig. 2) cannot disturb existing connections. The contact 188 will cut out the ringing relay RR.

In case the contact 50 of the register RE should have been closed by the action of the cam g,, the. switching organ would of course have moved downwardly instead of upwardly for the same reason that caused the horizontal motion, when 82 on the register RE was closed.

\Vhen the connector is arrested on the terminals of the wanted line, the relay HR de't nergizes and opens the circuit of the test relay lily R at contact 186 and if the wanted line is idle, the relay Inf/R is deenergized.

The ringing relay RR is energized over contacts 191, 101 and connects the ringing generator to the wanted line over the contacts of the test relay I i R When the called subscriber answers, the relay AR, disconnects the ringing-relay at contact 65, and at contact 64 opens the locking circuit of relay R, which therefore deeinergizes.

II", however, the wanted line is busy, the test relay Ly R, remains energized over contacts 250, 187, 217 and the ground on the test terminal of the wanted line. The application of ringing-current to the wanted line is therefore. prevented, and a busy interrupter T, is connected over contact 219 to a third winding on the relay AIL, whereby busy signaling currents are transmitted to the calling subscriber.

(7. The mechanical operation of the switching organ.

The switching organ is arranged upon a carriage or the like, bearing the slip springs S, and moved horizontally upon a rib or the like. The said slip springs will slip upon the two horizontal (L- and b-ribs of the connector.

The horizontal rib can in its turn be moved in the vertical direction by bearing in its ends carriages, sliding on horizontal ribs and bearing the slip springs S slipping upon the upper long aand b-ribs, which are in Fig. 2 shown horizontal, but which lie in the vertical direction.

Fig. 3 is a schematic view of a preferred embodiment of a device for moving the switching organ after the electromagnetic clutches M, K,, M K M K, and M K have been excited.

e, and e. are two shafts rotating in opposite directions and bearing rope pulleys or the like f and f over which the endless rope it passes. The rope pulleys f, and 7" can move freely on the shafts and can by means of the electromagnetic clutches M K, or M K be coupled to the shafts.

A. rack bar 71 is in such a way connected with the rope it that the bar can be moved vertically but not horizontally in relation to the rope. This cog bar i which bears two switching organs, the one directed downwardly, the other upwardly, meshes with a pinion 7c, displaceable but not turnable on the shaft Z, which by means of the bevel wheels 712 m and m. m, is connected to the shafts e, and 6,, rotating in opposite directions. The cog-wheels m, and m, turn freely upon the shaft Z, but can by the aid of the clutches M K, and M K be joined to this shaft.

The pinion It moves horizontally along shaft Z with the rack bar.

Assume that the shafts e,, e 6 and 6 rotate in the direction of the arrows, the switching organ will at the excitation of the clutch M K by the act-ion of the rack bar 2' together with the pinion is be moved to the right, as has before been described. At the moment the motion is finished, the clutch MB will be excited, so that the motion will be surely and momentarily stopped.

Should vertical motion clutch M K be excited, the rack bar 2' will descend and the switching organ arranged thereon will move downwardly as has been described above. \Vhen the motion is finished, MB will be operated.

Claims:

1. Selective switching apparatus comprising stationary terminals so arranged as to be identified in a two coordinate system, a switch member having selective movement in the two principal directions of said coordinate system, means for setting said member, means for causing said member to be set from a starting position to one side in a principal direction and means for causing said member to be set from the same position to the opposite side in the same prin cipal direction.

2. Selective switching apparatus comprising stationary terminals so arranged as to be identified in a two coordinate system, a switch member having selective movement in the two principal directions of said coordinate system, means for setting said member, means for causing said member to be set from its normal position to either side in one principal direction and means for causing said member to be set from an intermediate position to either side in the other principal direction.

3. Selective switching apparatus comprising a number of groups of stationary terminals so arranged as to be identified in a two coordinate system, a switch member having selective movement in the two principal directions of said coordinate system and located normally in acentral position relatively to said group of terminals, means for setting said member, means for causing said member to be set from a starting position to one side in a principal direction and means for causing said member to be set from the same position to the opposite sidein the same principal direction.

4. Selective switching apparatus comprising four groups of stationary terminals so arranged as to be identified in a two coordinate system, a switch member having selective movement in the two principal directions of said coordinate system and located normally in a central position relatively to said groups of terminals, means for setting said member, means for causing said member to be set from its normal position to either side in one principal direction and means for causing said member to be set from an intermediate position to either side in the other principal direction.

5. Selective switching apparatus comprising stationary terminals in the form of parallelly extending, uncovered wires, so arranged as to be identified in a two coordi nate system, a switch member having selective movement transversely to said wires in the two principal directions of said coordinate system, means for setting said member, and means for causing said member to be set from a starting position to either side in a principal direction.

6. Selective switching apparatus comprising four bundles of parallelly extending uncovered wires so arranged as to be identified in a two coordinate system, switch members having selective movement transversely to said wires in the two principal directions of said coordinate system and located normally in a central position relatively to said bundles of wires, machine driven means for setting said members, means for causing each member to be set from its normal position to either side in one principal direction and means for causing each member to be set from an intermediate position to either side in the other principal direction.

7. Selective switching apparatus comprising stationary terminals so arranged as to be identified in a. two coordinate system,

a switch member having selective movement in the two principal directions of said coordmate system, means for setting said mem- 

